The invention relates to a tread for a pneumatic tire.
It is a continuing goal in the art to produce tire tread designs that exhibit desirable properties with regard to traction, handling, braking and high speed performance while providing tires with a quieter and smoother ride. These properties, however, sometimes work against one another. For example, tires that have an aggressive tread pattern for wet and snow traction have a tendency to be noisier than tires that are designed for a smooth ride on smooth pavement.
Larger circumferential grooves and lateral grooves, and more open void areas in a tire help improve wet and snow traction, especially when the open void areas are in close relationship to large circumferentially-oriented grooves or aquachannels, or are positioned near the center of the tires. Large void areas, however, have a tendency to create more noise as the tire tread strikes the pavement.
The presence of void areas in the center of the tire, nevertheless, is important because water tends to build up in front of the tire at higher speeds (important for wet traction).
A tire tread has non-circumferential grooves, and void areas having a length and width of 1.2 to 5 times the average width of the non-circumferential grooves in the tread.
In the illustrated embodiment, the void areas are divided into branches, and the branches are separated by an island of tread rubber. The island has a variable width and rounded leading and trailing ends. The illustrated tire tread has a circumferential aquachannel which is disposed on the centerline of the tread and the island areas are located near the aquachannel. The island areas are angled with respect to the centerline of the tread.